JPH10317418A - Dozing device of bulldozer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To automatically doze in accordance with the working conditions and the quality of soil in a field site, by storing data regarding to respective relations such as a real traction force acting a blade and a position of the blade edge against the ground and the like, with respect to a real traveling distance of a bulldozer and controlling the posture of the blade on the basis of the data. SOLUTION: An operator's manual dozing is executed and four kinds of maps regarding the posture control of a blade 7 during the automatic drive mode, that is, a map showing a relation of a target traction force with respect to a real traveling distance, a map showing a relation of a target blade edge position relative to the ground with respect to the real traveling distance, a map showing a relation of a target full-load ratio of the blade with respect to the real traveling distance, and a map showing a relation of a target pitch angle with respect to the real traveling distance, are stored in a memory of a controller 18 as initial values by sensing at the teaching operation time. And the controller 18 controls the blade 7 to a required posture on the basis of these data stored in the memory.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dozing device for a bulldozer, and more particularly to a technique for automating excavation, soil transfer, and earth removal based on teach dosing by an operator.

[0002]

2. Description of the Related Art Conventionally, a dozing operation using a bulldozer is generally performed by manual operation of an operator who operates the bulldozer. The operation by the operator includes raising or lowering the blade,
Further, a tilt operation and a pitch operation are performed to keep the load of excavated soil applied to the blade constant while avoiding running slip (shoe slip) of the vehicle body.

[0003] However, such a dosing operation by manual operation by an operator requires skill, and even an expert operator has a problem that the operation frequency is high and a great deal of fatigue is involved. In order to solve such a problem, various techniques relating to automation of the dosing operation have been proposed and put into practical use. As an example of these automatic dosing techniques, for example, in Japanese Patent Publication No. 55-36776,
A device in which the lift amount of the blade is controlled in accordance with the load applied to the blade has been proposed.
Japanese Patent Publication No. 48855 discloses a technique in which the position of the blade with respect to the ground is controlled.

[0004]

However, the automatic dosing technique proposed in the prior art does not take into account the work form or soil properties of the site, and therefore it is difficult to correspond to the actual work form at the site. There is a problem that there is.

SUMMARY OF THE INVENTION The present invention has been made to solve such a problem, and an object of the present invention is to provide a dozing device for a bulldozer which enables automatic dosing in accordance with the work form or soil at the site. It is.

[0006]

In order to achieve the above object, a dozing apparatus for a bulldozer according to the present invention comprises: (a) an actual traction force applied to a blade with respect to an actual traveling distance of the bulldozer; Storage means for storing data relating to the respective relationships among the ground edge position, the fullness of soil and sand on the front of the blade, and the pitch angle of the blade; and (b) the blade is brought into a desired posture based on the data stored in the storage means. It is characterized by comprising blade control means for controlling.

In the present invention, the relationship between the actual running distance of the bulldozer, the relationship between the actual traction force applied to the blade, the relationship between the positions of the blades with respect to the ground, the relationship between the fullness of soil and sand on the front surface of the blade, and the relationship between the pitch angles of the blades. Such data is stored in the storage means in advance, and at the time of actual dosing work, the attitude of the blade is controlled based on the stored data. These data are preferably set by the teaching operation of the bulldozer and stored in the storage means. Thus, each of the data is created based on the manual dosing of the operator,
Since the dosing work is performed based on the created data, the excavation start point, the transition point from excavation to soil transfer, the soil discharge method, the land discharge point, and the control of a series of blades in the excavation work and soil transfer work are performed on site. It can be automated in accordance with the work form or soil type, and the position where the ground cutting edge reaches the ground after starting operation of the bulldozer is set as the excavation start point, and the soil on the front of the blade becomes full and the blade becomes full The position at which the pitch angle of the soil is in the soil carrying posture is the transition point from excavation to soil carrying, the position where the blade was raised or the pitch dump operation was performed during the soil carrying is taken as the earth discharging start point, and the position where the reverse movement started is the earth discharging Preferably, it is a point. The teaching operation may be performed not only manually but also manually by an operator during automatic dosing.

In the present invention, it is preferable that the data stored in the storage means is obtained by setting a minute distance width before and after a certain actual traveling distance, and obtaining an average value of the measured values in the minute distance width. As a result, hunting in control can be prevented even if the data obtained based on the teaching operation has a small fluctuation width.

In the present invention, the data of the actual traction force value for the actual traveling distance of the bulldozer stored in the storage means is set as the target traction force value in blade lift control for making the actual traction force applied to the blade coincide with the target traction force. Is preferred. Further, it is preferable that the data on the blade edge position relative to the actual traveling distance of the bulldozer be set as the target ground edge position in blade smoothness correction control for matching the blade edge position to the target ground edge position. Further, the data of the blade pitch angle with respect to the actual running distance of the bulldozer is preferably set as the target pitch angle in blade pitch control for matching the pitch angle in the earth removal mode of the bulldozer with the target pitch angle. Further, it is preferable that data of the fullness ratio of earth and sand on the front surface of the blade with respect to the actual traveling distance of the bulldozer is set as auxiliary data of the blade lift control or the blade pitch control.

Preferably, the data stored in the storage means is corrected by learning. Thereby, even if the work form or soil properties change sequentially with the progress of the dosing work, appropriate teaching can always be performed according to the change.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, a specific embodiment of a dozing device for a bulldozer according to the present invention will be described with reference to the drawings.

FIG. 1 is an external perspective view of a bulldozer according to an embodiment of the present invention, and FIG. 2 is a side view of the bulldozer.

In the bulldozer 1 of the present embodiment, a hood 3 accommodating an engine 20, which will be described later, and an operator's cab 4 for operating the bulldozer 1 are provided on the body 2 of the bulldozer 1. . A crawler belt 5 (the crawler belt on the right side is not shown) is provided on each of the left and right sides in the forward direction of the vehicle body 2 to move the vehicle body 2 forward, backward and turn. These two tracks 5
Each crawler belt 5 is independently driven by a corresponding sprocket 6 by a driving force transmitted from the engine 20.

A blade 7 is provided in front of the vehicle body 2. The blade 7 is supported by the distal ends of the left and right straight frames 8 and 9, and the base ends of the straight frames 8 and 9 are connected via trunnions 10 (the right trunnions are not shown). The blade 7 is pivotally supported by the vehicle body 2, whereby the blade 7 is supported so as to be able to move up and down with respect to the vehicle body 2. Furthermore, body 2
A pair of left and right blade lift cylinders 11 and 12 for raising and lowering the blade 7 are provided in front of both side portions. These blade lift cylinders 11 and 12 have base ends supported by a yoke 13 rotatably mounted on the vehicle body 2, and have other ends pivotally supported by the back surface of the blade 7. Blade pitch cylinders 14 and 15 are provided between the blade 7 and the left and right straight frames 8 and 9 to control the blade 7 to an excavation posture, a pitch dump posture and a pitch back posture, respectively, which will be described later. ing.

In the vehicle body 2, yoke angle sensors 16a and 16b for detecting the rotation angle of the yoke 13, that is, the rotation angles of the blade lift cylinders 11 and 12 (the yoke angle sensor on the right side is not shown). Each of the blade lift cylinders 11 and 12 is provided with stroke sensors 19a and 19b (illustrated in FIG. 3 only) for detecting a cylinder stroke of the blade lift cylinders 11 and 12. As shown in the hydraulic circuit diagram of FIG. 3, each of the blade lift cylinders 11, 12 is provided in the middle of a hydraulic line for supplying hydraulic pressure to the head side and the bottom side of the blade lift cylinders 11, 12, respectively.
Hydraulic pressure sensors 17 _H and 17 _{B for} detecting the head-side hydraulic pressure and the bottom-side hydraulic pressure, respectively. These yoke angle sensors 16a, 16b and stroke sensor 19
a, the output of 19b and the oil pressure sensor 17 _H, 17 _B are input to a controller 18 comprising a microcomputer.

Next, in FIG. 4 showing the power transmission system, the rotational driving force from the engine 20 is applied to the damper 2.
The torque is transmitted to a torque converter unit 23 having a torque converter 23a and a lock-up clutch 23b via a PTO 22 that drives various hydraulic pumps including the hydraulic pump 1 and the work machine hydraulic pump. Next, from the output shaft of the torque converter unit 23, the rotational driving force is transmitted to a transmission 24 that is, for example, a planetary gear wet multi-plate clutch transmission in which the input shaft is connected to the output shaft. The transmission 24 includes a forward clutch 2
4a, a reverse clutch 24b and first to third speed clutches 24c, 24d, 24e.
The output shaft 4 is rotated at three stages of forward and backward speeds. Subsequently, the rotational drive force from the output shaft of the transmission 24 is applied to a steering unit 25 having a pinion 25a and a bevel gear 25b, and a horizontal shaft 25e on which a pair of left and right steering clutches 25c and a steering brake 25d are arranged. A pair of left and right final reduction mechanisms 2
Each sprocket 6 is transmitted to the crawler belt 6 and travels on the crawler belt 5 (not shown in FIG. 4). Reference numeral 27 denotes an engine rotation sensor that detects the rotation speed of the engine 20, and reference numeral 28 denotes a torque converter output shaft rotation sensor that detects the rotation speed of the output shaft of the torque converter unit 23.

The rotation speed data of the engine 20 from the engine rotation sensor 27, the rotation speed data of the output shaft of the torque converter unit 23 from the torque converter output shaft rotation sensor 28, and the torque from a lock-up switch (not shown). Lockup (L / U) by switching lockup on / off of converter unit 23
-Torque converter (T / C) selection instruction is sent to the controller 18
(See FIG. 3).

Next, a circuit for operating the pitch of the blade 7 by the blade pitch cylinders 14 and 15 in this embodiment will be described with reference to FIG. In this hydraulic circuit, a lift operation circuit of the blade 7 by operating the blade lift cylinders 11 and 12 is omitted.

In this hydraulic circuit diagram, a first directional control valve 31A is connected to a discharge pipe of a fixed displacement hydraulic pump 30A for supplying hydraulic pressure to the left blade pitch cylinder 14, and a right direction blade pitch cylinder 15 is connected to the discharge pipe. A second directional control valve 31B is connected to a discharge pipeline of a fixed displacement hydraulic pump 30B that supplies hydraulic pressure. The discharge line of the assist hydraulic pump 32A is provided by an assist electromagnetic valve 33.
A is connected to the discharge pipeline of the hydraulic pump 30A via A, and the discharge pipeline of the assist hydraulic pump 32B is connected to the discharge pipeline of the hydraulic pump 30B via the assist electromagnetic valve 33B.

The discharge line of the pilot pump 34 is connected to a pilot control valve 36 of an operation lever 35. The pilot control valve 36 is connected to a left tilt limiting valve 38 via a pitch back control valve 37 and to a right tilt limiting valve 40 via a pitch dump control valve 39, respectively. Switching valve 4
1 is connected to the second directional control valve 31B. The pilot control valve 36 is connected to a first directional control valve 31 via a pitch back control valve 37, a left tilt restriction valve 38, a pitch dump control valve 39, and a right tilt restriction valve 40.
A is connected.

The operation lever 35 is provided with a pitch back changeover switch 35A and a pitch dump changeover switch 35B, and these changeover switches 35A, 35B are connected to the controller 18.

The output signal of the controller 18 is transmitted to the assist solenoid valves 33A and 33B, the pitch back control valve 3
7. Pitch dump control valve 39, left tilt limiting valve 38, right tilt limiting valve 40, and input to pitch / tilt switching electromagnetic switching valve 41 to control these valves.

When the controller 18 outputs the blade pitch back command, the pitch back control valve 37 is switched to the position A, and the pitch / tilt switching electromagnetic switching valve 41 is also switched to the position A. Command signal from the solenoid valve 33 for assist
A, 33B are input to the solenoid valves 33 for assist.
A and 33B are switched to the A position. For this reason, the discharge flow rates from the assist hydraulic pumps 32A and 32B join the discharge pipelines of the hydraulic pumps 30A and 30B. At this time, the pilot pressure from the pilot pump 34 is supplied to the operation section of the first direction control valve 31A via the pitch back control valve 37 and the left tilt restriction valve 38, and the pitch back control valve 37, the left tilt restriction valve 38 and the It is added to the operation unit of the second direction control valve 31B via the tilt switching electromagnetic switching valve 41. Thereby, the first directional control valve 31A and the second directional control valve 31B are switched to the position B, and the hydraulic pump 30
The pressure oil discharged from A flows into the head chamber of the blade pitch cylinder 14 through the first directional control valve 31A, and the pressure oil discharged from the hydraulic pump 30B passes through the second directional control valve 31B. It flows into the head chamber of the cylinder 15. As a result, the blade pitch cylinders 14 and 15 are shortened at the same time, and the blade 7 performs pitch back (backward tilt) quickly, so that the blade 7 shifts from the excavation posture to the soil transportation posture.

When the controller 18 outputs a blade pitch dump command, the pitch dump control valve 3
9 is switched to the A position, the pitch / tilt switching electromagnetic switching valve 41 is also switched to the A position, and the command signal from the controller 18 is supplied to the assisting electromagnetic valves 33A, 33A.
3B, the assist solenoid valves 33A, 33
B switches to position A. Therefore, the discharge flow rate from the assist hydraulic pumps 32A and 32B is
Merges into the discharge line of 30B. At this time, the pilot pressure from the pilot pump 34 is
And the first directional control valve 31 via the right tilt restriction valve 40
The operation unit A is connected to the operation unit of the second direction control valve 31B via the pitch back control valve 37, the left tilt restriction valve 38, and the pitch / tilt switching electromagnetic switching valve 41. Thereby, the first directional control valve 31A and the second directional control valve 31
B is switched to the position A, the hydraulic oil discharged from the hydraulic pump 30A flows into the bottom chamber of the blade pitch cylinder 14 through the first directional control valve 31A, and the hydraulic oil discharged from the hydraulic pump 30B is Two-way control valve 31
B flows into the bottom chamber of the blade pitch cylinder 15. Thereby, the blade pitch cylinder 14,
15 extend simultaneously, the blade 7 quickly performs a pitch dump (forward tilt), and the blade 7 shifts from the soil carrying posture to the earth discharging posture.

In the bulldozer 1 of this embodiment, first, teach dosing by an operator is performed, and automatic operation is performed based on data obtained at the time of teach dosing. Next, the procedure of the dosing operation of this embodiment will be described with reference to the flowchart shown in FIG.

S1: Manual dosing (teaching operation) of the operator is executed. S2: The following four types of maps (see FIG. 6) relating to the attitude control of the blade 7 in the automatic operation mode are stored as initial values in the storage unit of the controller 18 by sensing during the teaching operation. Here, the actual traveling distance L of the bulldozer 1 is measured by, for example, integrating the actual vehicle speed detected by a Doppler sensor or the actual vehicle speed detected from the rotation speed of a crawler sprocket. In addition, this actual mileage L is, other than this, the GPS
(Global Positioning System
m), the position may be measured by a position measuring means using a real-time kinematics method or a differential method.

A map showing the relationship between the actual running distance L and the target tractive force F ₀ (FIG. 6 (a)). The target tractive force F ₀ is determined based on whether the operation mode is an automatic excavation mode, an automatic soil transport mode, or an automatic excavation mode. The value differs depending on whether the mode is the earth removal mode. Namely, the target pulling force F ₀ indicates a value that is substantially constant value gradually increases and the drilling start point L ₀ in the excavation mode, and gradually decreases to a constant value from luck earth transition point L _a in luck soil mode And a value that monotonously decreases in the earth discharging mode. A map showing the relationship between the target ground cutting edge position に 対 す る_{0 and} the actual traveling distance L (FIG. 6B). Regarding the ground cutting edge position も₀ , whether the operation mode is the automatic excavation mode or the automatic soil transfer mode, The value differs depending on whether the mode is the automatic discharging mode. That is, the ground blade position [psi _0, in from the start of running up to the drilling start point L ₀ indicates a constant value, the value becomes a constant value gradually decreases and the drilling start point L ₀ in the excavation mode In the earth removal mode, the value gradually increases and becomes a constant value, and in the earth removal mode, the value monotonically increases. A map showing the relationship between the target blade full rate Q _{0 and} the actual travel distance L (FIG. 6C). Regarding the target blade full rate Q ₀ , whether the operation mode is the automatic excavation mode or the automatic soil transport mode The value differs depending on whether the automatic discharging mode is set. That is, the target blade full rate Q ₀ indicates a value that gradually increases from the excavation start point L ₀ in the excavation mode, indicates a constant value in the soil transfer mode, and a value that monotonously decreases in the earth removal mode. Map showing the relationship between the actual pitch L and the target pitch angle α ₀ (FIG. 6D). Regarding the target pitch angle α ₀ , whether the operation mode is the automatic excavation mode or the automatic soil transfer mode The value differs depending on whether the mode is the automatic discharging mode. That is, the target pitch angle alpha ₀ is from the start of running up to the drilling start point L _0, and the excavation mode indicates a constant value, and decreases gradually from luck earth transition point L _a in luck soil mode The value indicates a constant value, and indicates a value that monotonically increases in the discharging mode.

In creating these data,
The values of the target traction force F ₀ , the target ground edge position ψ ₀ , the target blade fullness Q _0, and the target pitch angle α ₀ for a specific travel distance Lp are, as shown in FIG. It is preferable to obtain from the average value of the measured values in the minute section (−ΔL to + ΔL).

[0029] In map created in this manner, ground cutting edge position is a position that has reached the ground (G.L) is set to the drilling start point L _0, the blade pitch angle will sediment blade front full luck soil luck soil transition point the position that became the attitude L _a
Is set to a position where the blade up or pitch dump operation is performed is set to the earth unloading start point L _b, the reverse is the start position is set to the high land point L _d.

S3: Of the data stored in this way, a map of the actual travel distance L to the target traction force F ₀ is set as the target traction force value in blade lift control (load control), and the actual travel distance L of the map is set. ~ Target ground edge positionψ
The map of ₀ is set as the target ground edge position in the blade smoothness correction control. Further, a map of the actual travel distance L to the target pitch angle α ₀ is set as a target pitch angle in blade pitch control. On the other hand, the actual traveling distance L
The map of the target blade full rate Q ₀ is used as auxiliary data in the blade lift control or the blade pitch control.

S4: When the target values of the blade lift control, the blade smoothness correction control, and the blade pitch control are set, automatic dosing is performed based on the target values.

In this automatic dosing, the blade lift control and the blade smoothing correction control are executed as follows.

First, the difference in traction force ΔF between the target traction force F ₀ and the actual traction force, the target opposite edge position ψ ₀ and the moving average straight frame absolute angle ψ ₂ (the vehicle body averaged with respect to the left and right straight frames 8 and 9) a straight frame relative angle [psi ₁ for 2, obtains the opposing edge position difference Δψ between the moving average value) of the predetermined time of the straight frame absolute angle obtained by the inclination angle of the vehicle body 2, as detected as the running slip And the case where it is detected that it is not running slip is performed as follows. 1) If it is detected that the vehicle is running, the blade 7
To avoid relief to running slip load of drilling押土applied to obtain the lift operation amount Q _S to raise the blade 7 by the slip control characteristic map (not shown). 2) When it is detected that the vehicle is not running, the following lift operation amounts Q ₁ and Q ₂ are obtained. The target tractive force F ₀ and the corrected actual tractive force (the actual tractive force minus the load correction corresponding to the inclination angle of the vehicle body 2)
The traction force difference ΔF between F, to obtain the lift operation amount Q ₁ of the blade 7 is raised or lowered as the corrected tractive force F from the load control characteristic map shown in FIG. 8 is equal to the target tractive force F _0. Then, the opposed edge positional difference Δψ between the target opposing edge position [psi ₀ and the moving average straight frame absolute angle [psi _2, the leveling control characteristic moving average map straight frame absolute angle [psi ₂ as shown in FIG. 9 obtaining a lift operation amount Q ₂ to which the blade 7 is raised or lowered so as to match the target opposing edge position [psi _0. Subsequently, the lift operation amounts Q ₁ and Q ₂ are calculated by subtracting the traction force difference Δ
Load as shown in Figure 10 by the F - obtaining a lift operation amount Q _T obtained by adding the weighted according leveling control weighting characteristic map.

In this way, the lift operation amounts Q _S , Q _T
Are obtained, the lift operation amounts Q _S and Q _T are supplied to a blade lift cylinder controller that controls the blade lift cylinders 11 and 12, and the lift valve actuator and the lift cylinder operation are performed based on the respective lift operation amounts Q _S and Q _T. Blade lift cylinder 1 via valve
The drives 1 and 12 are controlled to perform desired control for raising or lowering the blade 7.

On the other hand, the blade pitch control is executed at the time of the automatic operation of the earth discharging operation by pushing up (building up) the earth and sand. That is, when the actual traveling distance L reaches the earth discharging start point _Lb , the pitch control of the blade 7 is executed according to the map shown in FIG.

Next, relation map of the actual travel distance L~ target blade loading ratio Q ₀ is used as auxiliary data in the blade lift control or blade pitch control.
The fullness ratio Q is a pitch between the vertical reaction force (pressing force by the blade lift cylinders 11 and 12) F _V applied to the blade 7 and the ratio F _V / F _H of the horizontal reaction force (corrected actual traction force) F _H. Since there is a correlation with the angle α as a parameter (FIG. 11), the ratio of the vertical reaction force to the horizontal reaction force F _V /
It is calculated from F _H and the pitch angle α. Therefore, the luck earth transition point L _a and earth removal starting point L _b has been stored in advance, the fullness value of Q, is corrected by the value of if the ratio F _V / F _H other words, high and more accurate dosing Control can be performed.

In this embodiment, the teaching operation is performed only by the operator's manual.
The operation may be performed while the operator manually intervenes during automatic dosing.

In this embodiment, it is preferable that data obtained by the teaching operation is corrected by learning. By doing so, even if the work form or soil properties change sequentially with the progress of the dosing work, appropriate teaching can always be performed according to the change.

[Brief description of the drawings]

FIG. 1 is an external perspective view of a bulldozer.

FIG. 2 is a side view of a bulldozer.

FIG. 3 is a hydraulic circuit diagram showing a pitch operation circuit of the bulldozer.

FIG. 4 is a skeleton diagram of a power transmission system.

FIG. 5 is a flowchart illustrating a procedure of a dozing operation.

FIG. 6 is a graph showing a map related to blade attitude control in an automatic operation mode.

FIG. 7 is a diagram illustrating a method for creating map data;

FIG. 8 is a graph of a load control characteristic map.

FIG. 9 is a graph of a leveling control characteristic map.

FIG. 10 is a graph of a load-leveling control weighting characteristic map.

FIG. 11 is a graph showing the relationship between the ratio F _V / F _H and the fullness factor Q.

[Explanation of symbols]

1 bulldozer second body 5 crawler 6 sprockets 7 blade 10 trunnions 11, 12 blade lift cylinders 13 yoke 14 blade pitch cylinder 16a, 16b yoke angle sensor 17 _H, 17 _B oil pressure sensor 18 controller (storage means, the blade control means) 19a , 19b Slotalk sensor 20 Engine 23 Torque converter unit 24 Transmission 25 Steering unit 27 Engine rotation sensor 28 Torque converter output shaft rotation sensor 30A, 30B Hydraulic pump 31A First directional control valve 31B Second directional control valve 37 Pitch back control valve 41 Pitch / tilt switching electromagnetic switching valve L Actual traveling distance L ₀ Excavation start point L _a Soil transfer point L _b Discharge start point L _d Discharge land point

Claims (8)

[Claims] (A) For the actual traveling distance of a bulldozer, data relating to respective relationships among an actual traction force applied to a blade, a position of a cutting edge of the blade with respect to the ground, a fullness ratio of earth and sand in front of the blade, and a pitch angle of the blade are stored. And (b) a blade control means for controlling the blade to a desired attitude based on data stored in the storage means. 2. The bulldozer dozing apparatus according to claim 1, wherein each of the data is set by a teaching operation of the bulldozer and stored in the storage unit. 3. The bulldozer according to claim 2, wherein the data stored in the storage means is set with a minute distance width before and after a certain actual traveling distance, and is obtained from an average value of measured values in the minute distance width. Dosing device. 4. The data of the actual tractive force value for the actual traveling distance of the bulldozer stored in the storage means is set as the target tractive force value in blade lift control for matching the actual tractive force applied to the blade to the target tractive force. A dozing device for a bulldozer according to any one of claims 1 to 3. 5. The data of the position of the ground edge of the blade with respect to the actual traveling distance of the bulldozer stored in the storage means, the position of the ground edge of the blade in the blade smoothing correction control that matches the position of the ground edge of the blade with the target ground edge position. The dozing device for a bulldozer according to any one of claims 1 to 3, which is set as: 6. The data of the pitch angle of the blade with respect to the actual running distance of the bulldozer stored in the storage means, the target pitch in blade pitch control for matching the pitch angle of the bulldozer in the earth removal mode with the target pitch angle. The dozing device for a bulldozer according to any one of claims 1 to 3, which is set as an angle. 7. The data of the fullness of the earth and sand on the front of the blade with respect to the actual traveling distance of the bulldozer stored in the storage means is set as auxiliary data for the blade lift control or the blade pitch control.
Or a dozing device for a bulldozer according to 6. 8. A dozing apparatus for a bulldozer according to claim 1, wherein the data stored in said storage means is corrected by learning.